Ki-67, Cyclin E, and p16 INK4 Are Complimentary Surrogate Biomarkers for Human Papilloma Virus-Related Cervical Neoplasia

Abstract

Prior studies of Ki-67, cyclin E, and p16 expression have suggested that these biomarkers may be preferentially expressed in cervical neoplasia. This study examined and compared the distribution of staining for these three antigens in 1) normal and reactive epithelial changes, 2) diagnostically challenging cases (atypical metaplasia and atypical atrophy), 3) squamous intraepithelial lesions (SIL), and 4) high-and low-risk human papilloma virus (HPV) type-specific SIL. One hundred four epithelial foci from 99 biopsies were studied, including low-grade squamous intraepithelial lesions (LSIL; 24), high-grade squamous intraepithelial lesions (HSIL; 36), mature or immature (metaplastic) squamous epithelium (29), and atrophic or metaplastic epithelium with atypia (15). Cases were scored positive for Ki-67 expression if expression extended above the basal one third of the epithelium, for cyclin E if moderate to strong staining was present, and for p16 if moderate to strong diffuse or focal staining was present. HPV status was scored by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis of extracted DNA. Immunohistochemical findings were correlated with histologic and viral data. Overall, a histologic diagnosis of SIL correlated strongly with all of the biomarkers used (p <0.001). Positive scores for Ki-67, cyclin E, and p16 were seen in 68.4%, 96.7%, and 100% of LSILs and 94.7%, 91.6%, and 100% of HSILs, respectively. Positive predictive values of these three biomarkers for HPV were 82.4%, 89.5%, and 91.4%, respectively. The positive predictive value for HPV of either cyclin E or p16 was 88.7%. Strong diffuse staining for p16 was significantly associated with high-risk HPV-associated lesions. Normal or reactive epithelial changes scored positive for the three biomarkers in 7.7%, 8.0%, and 12%, respectively. Limitations in specificity included minimal or no suprabasal staining for Ki-67 in immature condylomas and occasional suprabasal staining of reactive epithelial changes (10%), diffuse weak nuclear cyclin E staining in some normal or metaplastic epithelia, and diffuse weak basal p16 staining and occasional stronger focal positivity in normal epithelia. Ki-67, cyclin E, and p16 are complementary surrogate biomarkers for HPV-related preinvasive squamous cervical disease. (Because cyclin E and p16 are most sensitive for LSIL and HSIL [including high-risk HPV], respectively, use of these biomarkers in combination for resolving diagnostic problems, with an appreciation of potential background staining, is recommended.)

Gastrointestinal immunophenotype in adenocarcinomas of the uterine cervix and related glandular lesions: a possible link between lobular endocervical glandular hyperplasia/pyloric gland metaplasia and ‘adenoma malignum‘

“…Recent studies have demonstrated that diffuse nuclear and cytoplasmic staining for p16 INK4 was significantly associated with high-risk HPV-related lesions. 17,18 Our study demonstrated frequent expression of this protein in 93% of UEAs, whereas MDAs less frequently expressed with a rate of 30%. Even when positive, positive cells were decreased and the staining intensity was weaker.…”

“…15,16 Recent studies have demonstrated that p16 INK4 immunohistochemistry is of diagnostic value for high-risk human papillomavirus (HPV)-related conditions including squamous intraepithelial lesions (SIL). 17 This protein is overexpressed as a consequence of incorporation of E7 derived from high-risk HPV, and it has been shown to be positive in invasive and in situ adenocarcinomas of the cervix, most of which are also considered to be HPV related. 18,19 The frequent location of LEGH/PGM, a putative precursor of MDA, in the portion of internal os away from the transformation zone, 6 prompted the authors to assume that a subset of cervical adenocarcinomas with gastric phenotype may have tumorigenesis distinct from high-risk HPV-related ordinary cervical adenocarcinomas.…”

MDM2 protein expression is a negative prognostic marker in breast carcinoma

“…8 It is possible that MDM2 expression in breast carcinoma is not a reflection of a genetic abnormality at the MDM2 locus but instead represents a host response to p53 loss of function; this is similar to the observation in cervical carcinoma that inactivation of Rb and p53 by HPV oncoproteins results in a dramatic increase in production of immunoreactive p16 by the tumour cells. 23,24 If this is the case, MDM2 immunostaining could be a valuable marker of loss of normal p53 function, and used in addition to direct assessment of the p53 gene and/or protein to identify abnormality in this critically important pathway.…”

Human papillomavirus genotyping and p16INK4a expression in cervical intraepithelial neoplasia of adolescents

“…6 The cyclin-dependent kinase (CDK) inhibitor p16 INK4a overexpression in high-grade CIN and cervical cancer appears to be related to viral integration during the neoplastic transformation of cervical cells. [12][13][14][15][16] The purpose of this study was to observe in CIN of adolescents from high-risk clinics in Mississippi the distribution of HPV types 16,18,31,33,35,45,52, and 58 that are considered oncogenic by the International Agency for Research on Cancer (IARC). 17 The relationship of HPV typing with p16 INK4a expression in different grades of CIN was evaluated in order to assess the ability of p16 INK4a immunostaining to identify transforming oncogenic viral infection and an increased risk of developing cervical cancer.…”